For one, choke collars are mostly for obedience training and unless a professional trainer has shown you how to utilize one you may not be using it or putting it on right.

And second, choke collars should really only be used on walks for dogs that already understand how to respond to the corrections from the collar.
If you're having to grab the collar to stop him from pulling and choking himself then you shouldn't really be using it on him because the collar is of no benefit to you and could cause throat injury, even without tightening.